While the major phenotypes of multiple sclerosis (MS) and relapsing–remitting, primary and secondary progressive MS have been well characterized, a subgroup of patients with an active, aggressive disease course and rapid disability accumulation remains difficult to define and there is no consensus about their management and treatment. The current lack of an accepted definition and treatment guidelines for aggressive MS triggered a 2018 focused workshop of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) on aggressive MS. The aim of the workshop was to discuss approaches on how to describe and define the disease phenotype and its treatments. Unfortunately, it was not possible to come to consensus on a definition because of unavailable data correlating severe disease with imaging and molecular biomarkers. However, the workshop highlighted the need for future research needed to define this disease subtype while also focusing on its treatment and management. Here, we review previous attempts to define aggressive MS and present characteristics that might, with additional research, eventually help characterize it. A companion paper summarizes data regarding treatment and management.

中文翻译：

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侵袭性多发性硬化症 (1)：表型定义

虽然多发性硬化症 (MS) 和复发-缓解型、原发性和继发性进展型 MS 的主要表型已被很好地表征，但具有活动性、侵袭性病程和快速残疾积累的患者亚组仍然难以定义，并且没有达成共识他们的管理和治疗。目前缺乏公认的侵袭性 MS 定义和治疗指南，引发了欧洲多发性硬化症治疗和研究委员会 (ECTRIMS) 2018 年关于侵袭性 MS 的重点研讨会。研讨会的目的是讨论如何描述和定义疾病表型及其治疗方法。不幸的是，由于无法获得将严重疾病与影像学和分子生物标志物相关联的数据，无法就定义达成共识。然而，研讨会强调了定义这种疾病亚型所需的未来研究的必要性，同时还要关注其治疗和管理。在这里，我们回顾了以前定义侵略性 MS 的尝试，并提出了可能通过额外的研究最终帮助表征它的特征。配套文件总结了有关治疗和管理的数据。